The invention relates to a device for bending an elongated dough product, comprising a first endless conveyance means which is suitable for receiving and conveying on a part of a conveyance surface thereof a row of products at a predetermined spacing from each other, the center line of each product running essentially perpendicular to the conveyance direction when it is received, a mandrel having a center line crossing the first conveyance means, means of movement for moving the mandrel in the conveyance direction in the conveyance path of the products and then back outside the conveyance path, and bending means arranged in a bending region on either side of the center of the conveyance path for bending a product around the mandrel.
A device of this sort is known from the European Patent Application EP No. 0,207,903. In the known device, the mandrel is formed by the end of a piston rod of a cylinder which is disposed above the first conveyance means and which is attached to a slide with which the cylinder can be moved to and fro in a vertical plane running through the center line of the conveyance path of the dough products. When the slide reaches the most upstream position thereof, the piston rod is forced out of the cylinder. The slide is then moved in the conveyance direction of the first conveyance means. During this movement, the mandrel formed by the end of the piston rod is able to intercept a dough product on the first conveyance means, after which the product can also be moved by the mandrel over the first conveyance means. In the bending region the mandrel is moved between two stationary shaping elements so that the dough product is bent essentially into a U shape therebetween. After the mandrel has passed the stationary shaping elements, the piston rod with the mandrel thereon is pulled up by the cylinder through a height which is greater than the thickness of the dough product and the slide is moved back to the most upstream position thereof. This cycle is continuously repeated.
In the known device, the slide requires time to move from the most downstream position to the most upstream position thereof. Since the slide, starting from the most upstream position thereof, also has to be back again in this position when the first conveyance means has been moved over the pre-determined spacing between the dough products, the slide has to be moved in the downstream direction more rapidly than the first transport means. This has the drawback that, while the slide is being moved in the downstream direction, a product entrained by the mandrel is able to rotate around the mandrel and may even come completely free of the mandrel. This means that a number of dough products received by the first conveyance means will not be bent and other products will be bent with insufficient uniformity. The products which have come free of the mandrel will also interfere with the satisfactorY operation of the device in the bending region.
In the known device for a row of succeeding dough products on the first conveyance means there is only one mandrel available, as a result of which the processing rate of the device is limited by the speed at which the slide can be moved to and fro.
In addition, the known device is only suitable for bending the dough products into a U shape. This presents a drawback since a bent dough product may become straighter during subsequent processing so that a desired U shape is not maintained, while it is often also desirable to bend the ends of the dough product towards each other and even over each other.
Another drawback is that the mandrel while descending thereof may be forced onto a passing dough product and will thereby damage said product. When the mandrel is pulled back again at the end of the bending region, it is then furthermore possible that the product remains attached to the mandrel, thereby interfering with the further operation of the device.
The object of the invention is to eliminate the drawbacks of the known device.